1. Field of the Invention
This invention is related to a detection system which provides a visible indication readily discernible by a person (consumers, quality assurance/quality control personnel, etc.) that a health care product has become contaminated by microbial organisms. More particularly, the invention is directed to a detection system which can be positioned in-situ in the health care product or be associated with the health care product packaging, such that microbial contamination can be detected without the use of external test equipment or laboratory facilities.
2. Description of the Prior Art
Microbial contamination is a major problem with consumer health care products such as nasal sprays, contact lens solutions, medication, shampoos, lotions, etc. Many microorganisms pose a significant health hazard. If a health care product is contaminated, a consumer may unexpectedly inoculate himself or herself with a harmful bacterium, virus, fungus, or the like, simply by using the product as is directed (e.g., washing contact lenses in a contaminated cleansing solution, inspiring a nasal spray, etc.). Once inoculated, the consumer may experience minor difficulties such as skin or eye irritation, infection, inflammation, as well as significantly worse problems such as blindness, destruction of nasal cells, vomiting, diarrhea, etc. In view of these potential dangers, many techniques have been developed for detecting-microbial contamination.
U.S. Pat. No. 3,206,317 to Golber discloses a system for detecting food spoilage wherein packaging line personnel wipe food samples on an indicator disc during packaging operations. The indicator disc may include nutrient culture media and a chemical reagent that changes color to indicate that a product is contaminated. In operation, pH changes or oxidation-reduction changes produced by bacteria which are wiped on the disc will cause the chemical reagent to change color.
U.S. Pat. No. 4,242,447 to Findl discloses a process for the rapid detection of bacteria in liquid samples. In operation, an inducing agent is added to a liquid medium to cause the production of a particular enzyme in bacteria that may be present therein. The enzyme reacts with a fluorescent conjugate that is ingested by the bacteria to produce a detectable signal.
U.S. Pat. No. 4,556,636 to Belly et al. discloses a composition for detecting bacteria in biological fluids such as urine and blood that includes a glucose substrate and a dye which is reduced and undergoes a color change when incubated in admixture with bacteria.
U.S. Pat. No. 4,812,393 to Goswami et al. discloses a detection process where dyes are used in assays for microorganisms. The dyes may be attached to blocking groups and can react with hydrolytic enzymes or cells containing the enzymes.
U.S. Pat. No. 4,874,695 to Pincus discloses that yeasts and other microorganisms can be detected by culturing samples containing the microorganisms, and then detecting whether microorganisms have been stimulated to produce particular enzymes.
U.S. Pat. No. 4,906,565 to Vossen discloses a bioluminescent assay which detects microbial nucleotides.
U.S. Pat. No. 5,004,682 to Roberts et al. discloses a method for detecting microorganisms in chlorine or bromine treated water wherein a lysing agent is added to the water and, if microorganisms are present, single stranded target nucleic acid molecules released from the lysed cells are detected.
U.S. Pat. No. 5,073,488 to Matner et al. discloses a method for determining the performance of a sterilization cycle. Matner et al. contemplate detecting the presence of enzymes which are produced by microorganisms to determine whether sterilization was performed correctly.
U.S. Pat. No. 5,093,235 to Williams et al. discloses an immuno-dye reagent and assay for the detection of endotoxin. The detection system utilizes anti-endotoxin antibodies.
Many of the detection systems described above are complex and require that the tests be performed in a laboratory. These type of detection schemes are only suitable for quality control at a packaging plant. While quality control at a packaging plant is important, products can become contaminated after shipping, but prior to consumer usage or during consumer usage. Hence, despite production quality controls, there is still a danger that the end-user can be accidentally exposed to harmful contaminants from a product that outwardly appears to be safe. Therefore, there is a need for a detection system which can be easily used and understood by a consumer at the product's point of use.
Furthermore, health care products are different from other consumable items such as food and water, and are different from biological fluids such as urine and blood. The type of microorganisms that survive and proliferate in a health care product such as a nasal spray or contact lens solution are typically quite different from those which might be a contamination problem in apple juice or might be identified in a blood sample. Chemical reagents which may identify one type of microorganism in one medium may not be suitable for identifying other microorganisms in another type of medium. In addition, many chemical reagents will only detect one type of microorganism, and are not useful for detecting a broad spectrum of microbial contaminants. In view of this, there is a need for detection schemes which are suitable for identifying a wide variety of the types of microorganisms that would be likely contaminants in health care products.